RESUMEN
Salmonellosis is a poultry industry and public health concern worldwide. Recently, Salmonella enterica serovar Heidelberg (SH) has been reported in broilers in Brazil. The effect of feeding a blend of three strains of Bacillus subtilis (PRO) was studied in broilers orally challenged (107 CFU/chick) or not with a SH isolated in south of Brazil (UFPR1 strain). Twelve male Cobb 500 broilers per pen were randomly assigned to six treatments in a 3 × 2 factorial experiment where PRO was added at 0, 250, or 500 g/ton of broiler feed and fed to either SH-challenged (SH Control, SH + PRO 250, and SH + PRO 500) or non-challenged birds (Control, PRO 250, and PRO 500). Broiler performance, histologic alterations in intestinal morphology, Salmonella quantification and immune cells counts in liver (macrophages, T CD4+ and T CD8+) were analyzed. Changes in the intestinal microbiota of broilers were also studied by metagenomics for Control, SH Control, SH + PRO 250, and SH + PRO 500 only. Feeding PRO at 250 or 500 g/ton reduced SH counts and incidence in liver and cecum at 21 days of age. It was observed that PRO groups increased the macrophage mobilization to the liver in SH-challenged birds (P < 0.05) but reduced these cells in the liver of non-challenged birds, showing an interesting immune cell dynamics effect. PRO at 250 g/ton did not affect gut histology, but improved animal performance (P < 0.05) while PRO at 500/ton did not affect animal performance but increased histologic alteration related to activation of the defense response in the ileum in SH challenged birds compared to control birds (P < 0.05). SH + PRO 500 group presented a more diverse cecal microbiota (Shannon-Wiener index; P < 0.05) compared to Control and SH Control groups; while SH + PRO 250 had greater ileal richness (JackkNife index) compared to Control (P < 0.05). PRO was effective in reducing Salmonella colonization in liver and cecum when fed at 250 or 500 g/ton to broilers inoculated with SH strain UFPR1. PRO promotes positive alterations in performance (at 250 g/ton), immune modulatory effect in the gastrointestinal tract, SH reduction, and intestinal microbiota modulation.
RESUMEN
Background: Salmonella control in poultry industry is of great importance to prevent foodborne diseases in humans. Theintense control of Salmonella Enteritidis caused an increased isolation of other serotypes as Salmonella Minnesota (SM),and it cannot be affi rmed that additives used to control Salmonella Enteritidis showed the same effi cacy to control of otherserovars. Therefore, the aim of this study was to evaluate the pathogenesis of SM in challenged broilers and the use ofdifferent organic acids for SM control in broilers.Materials, Methods & Results: In the present study, three experiments were conducted. In the fi rst experiment an in vivostudy to evaluate the pathogenesis of the SM in broilers where the birds were divided into 4 treatments with 15 animalseach: T1 - animals inoculated orally with SM, T2 - animals inoculated through feed with SM, T3 - in-contact birds cagedwith SM challenged birds and T4 - negative control. At 12, 24 and 48 h after the challenge, the crop, duodenum, cecumand liver were collected to detect SM. It was also collected fragments of jejunum, ileum and cecum for histopathologicaland immunohistochemistry analysis. At the microbiological evaluation 12 h after inoculation, it has already been possibleto observe the presence of SM in the crop, duodenum and cecum of birds challenged orally and through feed. Twentyfour h after contact with the challenged birds, the in-contact group have already shown the presence of SM in crop andduodenum. It was observed a signifi cant increase of goblet cells in the jejunum 24 h post inoculation (PI) in the orallyinoculated birds, and in the ileum 48 h PI in the feed challenged birds. In immunohistochemical evaluation, 12 h PI thebirds challenged orally have already shown a signifi cant increase in the number of CD3+ cells in the jejunum and 24 h PIa signifi cant increase of these cells in the ileum and cecum. In the second experiment an in vitro study was also performedto...
Asunto(s)
Animales , Células Caliciformes , Pollos/inmunología , Salmonella/inmunología , Salmonella/patogenicidad , Ácidos Orgánicos/análisis , Inmunohistoquímica/veterinaria , Pruebas de Sensibilidad Microbiana/veterinariaRESUMEN
Background: Salmonella control in poultry industry is of great importance to prevent foodborne diseases in humans. Theintense control of Salmonella Enteritidis caused an increased isolation of other serotypes as Salmonella Minnesota (SM),and it cannot be affi rmed that additives used to control Salmonella Enteritidis showed the same effi cacy to control of otherserovars. Therefore, the aim of this study was to evaluate the pathogenesis of SM in challenged broilers and the use ofdifferent organic acids for SM control in broilers.Materials, Methods & Results: In the present study, three experiments were conducted. In the fi rst experiment an in vivostudy to evaluate the pathogenesis of the SM in broilers where the birds were divided into 4 treatments with 15 animalseach: T1 - animals inoculated orally with SM, T2 - animals inoculated through feed with SM, T3 - in-contact birds cagedwith SM challenged birds and T4 - negative control. At 12, 24 and 48 h after the challenge, the crop, duodenum, cecumand liver were collected to detect SM. It was also collected fragments of jejunum, ileum and cecum for histopathologicaland immunohistochemistry analysis. At the microbiological evaluation 12 h after inoculation, it has already been possibleto observe the presence of SM in the crop, duodenum and cecum of birds challenged orally and through feed. Twentyfour h after contact with the challenged birds, the in-contact group have already shown the presence of SM in crop andduodenum. It was observed a signifi cant increase of goblet cells in the jejunum 24 h post inoculation (PI) in the orallyinoculated birds, and in the ileum 48 h PI in the feed challenged birds. In immunohistochemical evaluation, 12 h PI thebirds challenged orally have already shown a signifi cant increase in the number of CD3+ cells in the jejunum and 24 h PIa signifi cant increase of these cells in the ileum and cecum. In the second experiment an in vitro study was also performedto...(AU)